Calculated properties of GdNi intermetallic compound for the nitrogen liquefaction process: insight into ab-initio computations and Monte Carlo simulation

Abstract

Abstract Theoretical study on the ground state proprieties of GdNi intermetallic compound and its magnetic observable curves, as well as its magneto-caloric effect (MCE) was performed. It was established that the magnetic moment of Gd atom is found to be 7.11 μ B and the exchange coupling parameters are found to be J 1 = 3.7  meV and J 2 = 2.06 meV. Moreover, in good agreement with a recent experimental work, the magnetization, magnetization derivative and susceptibility curves confirmed that the studied sample undergoes a ferromagnetic ordering at T c = 70 K. Further, it was found that MCE in regard to the peak value of magnetic entropy ( − Δ S mag T ) around T c , can be enhanced with high magnetic fields. Besides, − Δ S mag Max (the maximum value of − Δ S mag T ) and RCP (Relative Cooling Power) attain maximum values of 17,13 JKg−1K−1and 549 JKg−1close to T c , respectively for external magnetic field of 5T, being in good agreement with the experimental ones. The present findings enable us to say that GdNi-based magnetic refrigeration can be considered as a promising technology for the nitrogen liquefaction process.